1. Technical Field
The present disclosure relates generally to a surgical stapling apparatus and, more specifically, to a surgical stapling apparatus having a single trigger for approximating anvil and cartridge assemblies and for ejecting an array of staples from the cartridge assembly.
2. Background of Related Art
Surgical stapling instruments used for applying parallel rows of staples through compressed living tissue are well known in the art, and are commonly used, for example, for closure of tissue or organs prior to transection, prior to resection, or in anastomoses, and for occlusion of organs in thoracic and abdominal procedures.
Typically, such surgical stapling instruments include an anvil assembly, a cartridge assembly for supporting an array of surgical staples, an approximation mechanism for approximating the anvil and cartridge assemblies, an alignment pin assembly for capturing tissue between the cartridge and anvil assemblies and for maintaining alignment between the cartridge and anvil assemblies during approximation and firing, and a firing mechanism for ejecting the surgical staples from the cartridge assembly. The approximation mechanism and the firing mechanism generally include distinct actuators for effecting approximation and firing of the staples. The alignment pin assembly can be manually operated to advance an alignment pin from the cartridge assembly into engagement with the anvil or, alternatively, the alignment pin assembly can be automatically actuated upon operation of the approximation mechanism. In instruments having a manually operated alignment pin assembly, the actuator for the alignment pin assembly is disposed at a location spaced from the handle of the instrument.
U.S. Pat. No. 4,930,503 to Pruitt discloses such a surgical stapling instrument. Pruitt's instrument includes a manually operated alignment pin assembly, an approximation mechanism including a rotatable knob actuator and a firing mechanism including a pivotable trigger. In use, a surgeon must first approximate the anvil and cartridge members by rotating the knob actuator. Next, the surgeon can advance the alignment pin assembly by advancing a knob supported on the central body portion of the instrument. Thereafter, the instrument can be fired by pivoting the trigger towards a stationary handle of the instrument.
U.S. Pat. No. 5,697,543 to Burdorff also discloses a surgical stapling instrument having an approximation mechanism, a firing mechanism and an alignment pin mechanism. The approximation and firing mechanisms each include a distinct pivotable trigger actuator. The alignment pin mechanism is operatively associated with the approximation mechanism such that upon actuation of the approximation mechanism, the alignment pin assembly is automatically advanced.
Known prior art surgical staplers are lacking in several respects. Firstly, the use of multiple actuators to effect approximation and firing of the instruments complicate the manufacture and operation of the instrument and, in most cases, require the surgeon to use two hands to hold and operate the instrument. Secondly, the instruments in which the alignment pin assembly is operatively associated with the approximation mechanism require that the instrument be approximated to advance the alignment pin assembly, despite the fact that a surgeon may prefer to advance the alignment pin assembly prior to approximation. In contrast, the instruments in which the alignment pin assembly is manually advanced typically require the surgeon to use a second hand to actuate the alignment pin assembly.
Accordingly, a continuing need exists for a surgical stapling instrument which can be operated by a surgeon with a single hand and which includes an alignment pin assembly which can be automatically or manually advanced.